Field of the Invention
This invention relates to fabrication of miniature structures and more particularly relates to method for producing mechanically flexible silicon substrate.
Description of the Related Art
Nanostructured elements of single-crystal silicon, in the form of substrates, wires, ribbons, and particles, are of interest for a number of applications in electronics, optoelectronics, sensing, and other areas. Stretchable and easily deployable silicon based integrated circuits (ICs) will facilitate the development of many new technologies in the areas of implantable biomedical applications, renewable energy, sensors and smart cards.
Approaches that rely on the lithographic processing of top surfaces of semiconductor wafers enable well-controlled thicknesses, widths, lengths, and crystallinity. These methods can form membranes, tubes, and ribbons, with thicknesses in the micrometer to nanometer range.
One common practice to fabricate mechanically flexible nanoribbons (substrate) is to use wet etching on a (111) Si or silicon-on-insulator (SOI) wafer and then transfer the product onto a plastic substrate. However, cost of the process is high due to the use of high-cost (111) Si or SOI wafer. Another similar common practice to fabricate mechanically flexible substrate is to use a back grinding process. Back grinding eliminates the potential to recycle the remaining part of the wafer that is not included in final product of the mechanically flexible substrate. Therefore, there exists a need for low lost fabrication of mechanically flexible mechanically flexible silicon substrate.